Threading attachment



C. A. JOHNSON. THREADING ATTACHMENT.

APPLICATION FILED DEC. 12, 1917.

Patented Sept. 28, 1920.

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% ATTORNEY.

CHARLES A. JOHNSON, OF UNIONVILLE, CONNECTICUT.

THREADING ATTACHMENT.

Specification of Letters Patent. Patented Sept. 28, 1920.

Application filed December 12, 1917. Serial No. 206,734.

. To all whom it may concern:

Be it known that I, CHARLES A. JOHNSON, a citizen of the United States, residing at Unionville, in the county of Hartford, State of Connecticut, have invented a new and Improved Threading Attachment, of which the following is a specification.

My invention relates to the class of devices commonly used as an attachment for machines and with which threads are produced on rods or small pieces of material, and an object of my invention, among others, is to provide improved means for holding the threading dies and for securing the necessary adjustments thereof. One form of device embodying my invention, and in the construction and use of which the objects herein set out, as well as others, may be attained, is illustrated in the accompanying drawings in which:

Figure 1 is a side view of a threading die holder embodying my invention.

Fig.2 is an end view of the same.

Fig. 3 is an end view looking from the right of the device as seen in Fig; 1 and with parts broken away on different lines in cross section to illustrate the construction.

Figs. 4 and 5 are detail end views of the die holder illustrating the functions of the interchangeable die block.

My invention is illustrated and described herein in connection with a threading tool of the general character of that shown in my Patent No. 1,250,185, dated December 18, 1917, thepresent invention being especially applicable to the device shown in said patent to which reference is hereby made for an understanding of such parts of the main device as may not be specifically illustrated in a manner that will be readily understood by those skilled in the art, the threading tool having relative rotation as well as relative lengthwise movement with respect to the article that is being threaded.

The spindle 10 is secured in any suitable manner in the body 11 of the improved threader that is secured to the spindle with its head 12 preferably resting against a flange 13 on' the spindle. An annular groove 14: extends around the body, and holes 15 are formed through the body to receive die holders 16 located in the body and extending therethrough, said holders being disposed at re ular intervals apart around the body.

These holders are all of similar construction and a description of one will answer for all. They are of cylindrical shape as to those parts located in the holes 15, the ends of the holders, however, being somewhat irregular in shape in cross section. An opening for a cutter to extend diametrically across the holder is made at or near its end. In the preferred form of construction this opening is in the form of a groove 17 made in the end of the holder and of a width to receive a cutter 18, and a die block comprising a seat for the cutter and a clamp to hold it in place, which clamp and die block will be hereinafter described.

In the cutting of threads of different character as to coarseness, fineness, difference in pitch or difference in other respects, the cutters must be set in different positions, and the angular position of the cutters in different directions must be changed to suit the character of the thread to be cut, the change of this angular position of the cutter both crosswise and lengthwise thereof being required.

In structures heretofore employed, in

. order to effect the changes above mentioned,

it has been necessary to substitute new sets of holders having means to receive the cutters set in the particular position required. With my improved device I have provided very simple and effective means whereby cutters to perform different characters of work may be readily changed in the holders, and to this end a groove 19 is formed in one wall of the groove 17 to receive the tongue 20 from a die block 21. The meeting surfaces of the die block and thread cutter are grooved, the grooves on the thread cutter running out at the beveled cutting end 22 thereof. For providing threads of different character the thread cutters must be formed to produce such threads, and the threads running along the face of the cutters to the endthereof, will, therefore, be required to be of different pitch for different operations. This may be easily done with my improved device herein illustrated and described, as

the die blocks 21 may be readily removed and other ones substituted to have a threaded surface to correspond with that on a thread cutter to cut any particular thread. For instance, as illustrated in Figs. 4 and 5,

. in operating upon blanks of different size the angular position of the tool crosswise of the holder must be changed; likewise, as Wlll be readily understood, in cutting a thread of the same pitch upon blanks of different size and hence using the same cutter, owing to j the difference in length of a thread extending once around the blank, the angle of such 'thanthat upon the smaller blank.

thread will be changed, the angle of the thread onthe larger blank being much less thus be seen that the interchangeable die block, hereinabove described, is of particular value in enabling these changes of the cutters to be quickly effected.

As a means for securing the cutters in place a clamp 23 is located in the groove in I the. end of the holder, this clamp having a place.

rocking lug 24 fitting a recess 25 located in the Wall of the groove 17 opposite that hav- 7 ing. the groove 19. The end26 of the clamp is formed to press against the thread cutter and the opposite end of the clamp bears a clamp screw 27 extending through the clamp and adapted to be forced against the thread cutter, the latter being thus held securely in shorter as by repeated grinding, that end opposite the point 22 will pass inward beyorid the clamp screw, then a separate piece maybe located underneath the clamp screw and the end 26 thereof still clamping the tool the thread cutter may thus be practically entirely used up. Each holder has an arm 28 eii ten'ding from that end opposite the thread cutters, this arm having a recess 29 to receive the enlarged end 30 of an adjusting finger. This finger is of angular shape, the part projecting from the enlarged end 30 in position to receive the thrust of an adjusting screw 33. The other part or tip 32 of the finger projects against an actuating-cam 34 formed on the actuator hereinbefore re ferred to and which is secured to the end of an actuating rod 35 projecting within the spindle'of the machine and extending into the body 11 of my improved threading tool.

' referred to and the arm 28, a rocking movement of the holders to bring the thread cutters into engagement with a piece of work or to disengage them therefrom. Owing to the different sizes of the pieces of work 36, 37 the angle at which the thread cutters 18 It will When the thread cutter becomes.

must be located in the holders are different, and the removable blocks 21 enable a proper support of the thread cutters to engage the different sizes of work, and especially as shown in Figs. 4 and 5 of the drawings.

The enlarged end 30 of the adjusting finger is cut-away, as shown in Fig. 3 of the drawings, and a holding screw 38 entering the end of the arm. 28 has the edge of its head overlying said cut-away portion and thus removably secures the finger in place.

My improved device forming the subject matter of this case has been described herein as attached tothe spindle of, a-lathe, which spindle may be rotated but it will be obvious that the device may be attached to a nonrotative part and that the work may be rotated in a manner that will be well understood by those skilled in the art.

Likewise the opening and closing movements of the dies may be effected by means other than those shown hereim and which means will be readily understood by those skilled in the art.

In accordance with the provisions of the patent statutes, I'have described the principics of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the device shown is only illustrative, and that the invention can be carried out by other means within the scope of the appended claims.

I claim:

1. A threading attachment including a body part, a die holdermovably mounted in the body part and having an opening for a thread cutter, a rocking clamp mounted in said opening and extending lengthwise thereof .and of a cutter therein to clamp said cutter, and means for securing said clamp. I

2. A threading attachment including a body part, a die holdermovably mounted in the body part and having an opening for a thread cutter, a clamp mounted. for rocking clamping action in said opening and extending lengthwise thereof and of a cutter therein to clamp said cutter, and means at one end of the clamp to force its opposite end into contact with the cutter.

3 A threading attachment including a body part, a die holder movably mounted in the body part and having an opening for a thread cutter, a; clamp mounted for rocking clamping action insaid opening and extending lengthwise thereof and of a cutter therein to clamp said cutter, and a screw at one end of the clamp extending into the clamp to force its opposite end into contact with the cutter. a

- 4; threading attachment including a body part, a die holder movably mounted in the body part and having an opening for a thread cutter, a clamp, mounted for rocking clamping action in said opening and extending lengthwise thereof and of a cutter therein to clamp said cutter, and a screw extending through the clamp at its end to force its opposite end into contact with the cutter.

5. A threading attachment including a body part, a die holder movably mounted in the body part and having an opening for a thread cutter with a recess in the wall of the opening, a clamp extending lengthwise of a cutter both of which are mounted in said opening, said clamp having a rocking lug located in said recess, and means for rocking the clamp on said lug to force the clamp into contact with the cutter.

6. A threading attachment including a body part, a die holder movably mounted in the body part and having an opening for a thread cutter with a recess in the wall of the opening, a clamp extending lengthwise of a cutter both of which are mounted in said opening, said clamp having a rocking lug intermediate its ends located in said recess, and means on one side of said lug for forcing the clamp on the opposite side of said lug into contact with the cutter.

7. A threading attachment including a body part, a die holder movably mounted in the body part and having an opening for a thread cutter with the recess in the wall of the opening, a clamp extending lengthwise of a cutter both of which are mounted in said opening, said clamp having a rocking lug located in said recess, and a screw engaging the clamp on one side of said lug to force the clamp on the opposite side of said lug into contact with the cutter.

8. A die holder having an opening inwardly from one end thereof for a thread cutter, a rocking clamp mounted in said opening and having a lug resting against one wall-of the o enin and com risin a fulcrum for said clamp, and means located at one end of said clamp to rock it on said fulcrum and force its opposite end into contact with the cutter.

9. A die holder having an opening extending inwardly therefrom one end thereof for a thread cutter one wall of said opening having a recess therein, a clamp mounted in said opening between a ,cutter therein and a wall thereof and having a lug resting in said recess to form a fulcrum for said clamp, and means for forcing the clamp against the cutter and the latter toward the wall of said opening that resists such force.

10. A die holder having an opening in one end for a cutter one wall of-said 0pen ing being threaded and said cutter having threads formed along its front face, a clamp mounted in said opening between the back of the cutter and one wall of the opening, and means for forcing the clamp against the unthreaded side of the cutter and the threaded face thereof against the threaded wall of said opening that resists such force.

11. A threading attachment including a body part, a die holder movably mounted in the body part and having an opening for a thread cutter with a groove in the wall of said opening, a block having a tongue to enter said groove and with its opposite surface threaded to correspond with the threads on a. thread cutter, and means for clamping a cutter against said block and for forcing said tongue into the groove to securely hold both the block and cutter in place.

12. A threading attachment including a body part, a die holder movably mounted in the body part and having an opening for a thread cutter, said opening having a groove in one wall and a recess in the opposite wall, a block having a tongue to enter said groove and threaded on the side opposite the tongue to correspond with the threads on a thread cutter, a rocking clamp having a lug located in said recess, and means for forcing the clamp on one side of said lug into contact with a cutter.

13. A threading attachment including a body part, a die holder removably mounted in the body part, means for securing a thread cutter to said holder, means for moving said holder in the body part, an arm projecting from the holder, a finger loosely and removably located for swinging movement in the recess in the holder and projecting therefrom, and a screw interposed between the finger and arm to impart swinging movement to said finger to vary the distance between said parts.

14. A threading attachment including a body part, a die holder movably mounted in the body part and having an opening for a thread cutter, a block located in said open ing to serve as a rest for a thread cutter, said block and cutter having interengaging parts. to prevent relative movement thereof, means for removably securing the block in place whereby by substitution of different blocks the angular position of a cutter for cutting a thread of the same character on blanks of different size may be changed, and means for securing the cutter against said block.

15. A. threading attachment including a body part, a die holder movably mounted in the body part and having an opening for a thread cutter, a block located in said opening to serve as a rest for a thread cutter, said cutter and block having interengaging ribs and grooves extending lengthwise of the cutter, means for renovably positioning the block whereby by substitution of different blocks the angular position of a cutter for cutting a thread of the same character on blanks of different size may be changed,

and means for securing the cutter in )lace.

CHARLES A. J OHNSN. 

